Backswimmer

Notonectidae family backswimmer, so named because they swim upside-down. They pack a bite — more of a tube-like harpoon’s jab — belying their size. These bugs go after prey bigger than themselves. Some species hunt tadpoles and fish, others other insects. I understand their bite stings like the dickens. Their hid legs are like oars on a scull.

Sometimes these are called water boatmen, but true water boatmen are of the Corixidae family and swim right-side up.